JP7259682B2 - wireless communication system - Google Patents

Description

The present invention relates to wireless communication systems.

It has a wireless communication system consisting of a master unit and multiple slave units wirelessly connected to the master unit, and a center device. There is a remote monitoring system that notifies a central device of a leakage alarm, low battery level alarm, etc. via a master unit (Patent Document 1).

In this remote monitoring system, communication is performed between the center device and the master unit via a public line such as radio or cable. Radio communication within a radio communication system composed of “machines” is performed using specified low-power radio or the like.

Each child device is arranged so as to form one hierarchy for each unit of distance, for example, about 100 m from the parent device. In addition, the center device stores a plurality of communication route information composed of a parent device and a child device, and each child device stores communication partner information (terminal ID of a higher-level terminal, etc.) for each communication route. .

Creation of a communication route for a child device is performed, for example, by the following method. When a child device is newly installed, the child device first calls surrounding terminals, that is, broadcasts a route search message to which the terminal ID (identification information) of the own terminal is added. Then, it is checked whether or not there is a response from the surrounding terminals (parent device, child device) within a predetermined time.

If there is a response within a predetermined time, a terminal with good communication conditions is selected from the terminal ID contained in the response message, the received field strength of the route search message, etc., and finally one or more communication route information ( communication partner information), that is, the terminal ID of the host terminal to be the communication partner, etc. are stored in the storage unit of the own terminal for each communication route.

Also, based on the received electric field strength acquired at this time, for example, communication route numbers (priority) such as the first communication route and the second communication route are assigned in descending order of the received electric field strength. Then, a telegram requesting registration of these communication routes is transmitted to the center device. The center device receives the registration request message and registers the communication route.

JP 2010-87761 A

As shown in FIG. 10, the communication route to the higher-level terminal selected by the child device when constructing a wireless communication system centered on the parent device is to select a terminal installed in the direction of the parent device. is preferable as the aggregation route to the parent machine.

However, in the conventional communication route creation method, since the newly installed child device does not know the direction of the response terminal, it is not possible to secure a communication route aggregated in the direction of the parent device. As described above, there are cases in which a newly installed child device (hatched) selects a terminal in the opposite direction to the parent device. In this case, the communication route is not aggregated in the direction of the parent unit, but dispersed, resulting in a complicated configuration, which poses a maintenance problem in that it is difficult to grasp the influence of the surrounding communication route after the child unit is installed. .

SUMMARY OF THE INVENTION The present invention has been made to solve such problems. To create a communication route aggregated in the direction of a base unit when creating a communication route of a parent device.

The present invention is a wireless communication system comprising a parent device and a plurality of child devices wirelessly connected to the parent device, wherein each child device broadcasts a route search message to surrounding terminals when collecting routes. a response receiving means for receiving a response message including the terminal ID and location information of the terminal and the location information of the parent device transmitted from the surrounding terminals that received the route search message; A direction determining means for determining the direction of the base unit and the response terminal relative to the self based on the position information of the base unit and the response terminal obtained by the self and the own position information acquired by the self, and receiving response messages from a plurality of surrounding terminals. In this case, the wireless communication system includes response terminal selection means for selecting a response terminal closer to the base unit as a higher-order terminal having a higher priority.

According to the present invention, in a wireless communication system comprising a parent device and a plurality of child devices wirelessly connected to the parent device, communication is aggregated in the direction of the parent device when creating a communication route for the child device. You can create routes.

It is a figure showing composition of a remote monitoring system concerning an embodiment of the present invention. 2 is a block diagram showing a schematic configuration of a slave device in the remote monitoring system shown in FIG. 1; FIG. 10 is a flowchart showing route collection processing for a newly installed child device; FIG. 10 is a diagram showing that a newly installed child device can acquire location information of a parent device and a responding child device from a response to a call to a surrounding terminal; It is a figure which shows the response message|telegram with respect to an appeal. FIG. 10 is a diagram showing parent device location information and response terminal location information acquired by a newly installed child device; FIG. 11 is a flow chart showing response terminal selection processing of a newly installed child device; FIG. FIG. 10 is a diagram showing a state in which a newly installed slave acquires position information of surrounding terminals and grasps the positions of surrounding terminals centering on its own position; FIG. 10 is a diagram showing a display mode of the positional relationship of the parent device and the response child device with respect to the newly installed child device; FIG. 10 is a diagram showing a case where a communication route aggregated in the direction of a base unit can be created in a conventional communication route creating method; FIG. 10 is a diagram showing a case where a communication route aggregated in the direction of a base unit cannot be created in a conventional communication route creation method;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
<Configuration of remote monitoring system>
FIG. 1 is a diagram showing the configuration of a remote monitoring system according to an embodiment of the invention.
This remote monitoring system is used, for example, for automatic meter reading of gas meters and water meters. and a wireless communication system.

Communication between the base unit 1 and the center device 100 is performed via a commercial communication line such as a mobile phone line, and wireless communication within a wireless communication system composed of the base unit 1 and the handsets 2 in the first to third stages. is carried out using specified low-power radio, etc. In the following description, when the parent device and the child device are not distinguished, they are referred to as terminals.

Sensors such as gas meters, water meters, and gas leak detectors are connected to each slave unit. Using the child device as a relay child device, it reports to the parent device 1 and further to the center device 100 via the parent device 1. - 特許庁

In FIG. 1, the number of slave units in the wireless communication system is three, but there are also configurations with two stages and five or more stages. Also, in FIG. 1, each child device has a single host terminal, but there is also a configuration having a plurality of host terminals.

<Schematic configuration of child unit>
FIG. 2 is a block diagram showing a schematic configuration of a slave unit in the remote monitoring system shown in FIG. 1;

As illustrated, the handset 2 includes a CPU 21 as a control unit, a ROM 22, a RAM 23, an operation unit 24, a display unit 25, a specific low-power radio unit 26, a meter I/F (interface), and a ROM 22, a RAM 23, which are each connected to the CPU 21. 27 and an external I/F 28 , and an antenna 29 is connected to the specific low-power radio unit 26 . The handset 2 also includes a power supply unit 30 that supplies power to each unit.

The CPU 21 is composed of, for example, a microprocessor and its peripheral circuits, and performs control of the entire slave unit, arithmetic processing, etc., and by operating each part, the calling means, response receiving means, direction determination means, and It implements response terminal selection means, distance determination means, display means, and cancellation means. The details will be described later.

The ROM 22 stores a control program necessary for operating the handset 2 . That is, for example, in the route collection process (FIG. 3) described later, the location information of the parent device and the response child device, and the received electric field strength of the route search message in the response child device are stored, and the parent device and the response A program is stored that determines the distance and direction of the slave and selects the responding slave located in the direction of the master.

RAM23 becomes a work area when CPU21 performs various arithmetic processing. Further, during the route collection process, positional information of the response child device and the parent device, positional difference information, response child device ID, etc. are held as a route table. In addition, it holds information used for determination when selecting a response terminal as a higher-level terminal, such as the strength of the received electric field of the route search telegram in the response slave.

The operation unit 24 includes buttons, switches, etc., and is a user I/F for inputting predetermined settings for the child device 2 . The display unit 25 is composed of an LED and the like, and is a user I/F that displays the operating state of the handset 2 and the like.

The specified low-power radio unit 26 performs radio communication with surrounding terminals via the antenna 29 . Meters such as a gas meter and a water meter are connected to the meter I/F 27 . A position information measuring device such as a GPS receiver is connected to the external I/F 28 .

<Route Collection Processing for Newly Installed Child Units>
FIG. 3 is a flow chart showing the route collection processing of the newly installed child device, and FIG. It is a figure which shows that a positional information can be acquired. Moreover, FIG. 5 is a figure which shows the response message|telegram with respect to an appeal.

As shown in FIG. 3, the newly installed child device first calls for route collection to surrounding terminals. That is, a route search message to which the terminal ID (identification information) of the own terminal is added is broadcast to the surroundings (step S1).

Here, as shown in FIG. 4, the newly installed handset 2a makes a call. Base unit 1 and child units 2b, 2c, 2d, and 2e are present in the surroundings, and base unit 1 holds its own position information (base unit position information). holds the position information of each device and the position information of the base device 1 included in the response message from the base device 1 to the call at the time of installation. The child devices 2b, 2c, 2d, and 2e can transmit the positional information of the base device 1 and their own device held by each of them as a response message to the call.

The child device 2a receives the response message containing the location information of the response terminal and the parent device and the received field strength of the challenge (step S2). That is, as shown in FIG. 5, this response telegram includes a sender ID (terminal ID of the responding terminal), base unit location information, own unit location information (self-location information of the responding terminal), and received electric field strength. It contains information (received electric field strength information of the route search message at the response terminal). Here, as shown in FIG. 4, slave units 2b, 2c, 2d and 2e transmit response messages.

Next, handset 2a determines whether the received electric field intensity of the response terminal is equal to or greater than a predetermined value, that is, whether the communication conditions with the response terminal are good or bad (step S3). When it is determined that the value is equal to or greater than the predetermined value (step S3: Yes), the difference between the location information of the own terminal and the parent device is calculated (step S4), and then the difference between the location information of the own terminal and the response terminal is calculated. (step S5).

Here, in step S3, it is determined that the received electric field intensity in the child devices 2b, 2c, and 2e is equal to or greater than a certain value, and in steps S4 and S5, the location information contained in the response message from the child devices 2b, 2c, and 2e is determined. is used to calculate the difference in position information.

FIG. 6 is a diagram showing parent device location information and response terminal location information acquired by a newly installed child device. As shown in the figure, the master device 1 acquired by the slave device 2a, the slave device 2a (own device), the slave device 2b (response slave device), the slave device 2c (response slave device), and the slave device 2e (response slave device) Location information is as follows.
Base unit 1: 35.4444 north latitude, 139.2222 east longitude
Slave unit 2a: 35.2222 north latitude, 139.2233 east longitude
Slave unit 2b: 35.3333 north latitude, 139.1111 east longitude
Child machine 2c: 35.3333 north latitude, 139.2233 east longitude
Child machine 2e: 35.1111 north latitude, 139.4444 east longitude

Therefore, the positional difference information between the parent device 1, the child devices 2b, 2c, 2e and the child device 2a is obtained by subtracting the positional information of the child device 2a from the positional information of the parent device 1, the child devices 2b, 2c, 2e, respectively. is as follows.

Position difference information between parent device 1 and child device 2a: latitude difference information = 00.2222, longitude difference information = -00.0011
Position difference information between child device 2b and child device 2a: latitude difference information=00.1111, longitude difference information=-00.1122
Positional difference information between handset 2c and handset 2a: latitude difference information=00.1111, longitude difference information=0
Position difference information between child device 2e and child device 2a: latitude difference information=-00.1111, longitude difference information=00.2211

Returning to the description of FIG. Next, slave device 2a executes response terminal selection processing (step S6) and terminates route collection processing. Details of the response terminal selection process will be described later. If the received electric field strength of the response terminal is less than the predetermined value in step S3 (step S3: No), it is determined that the route collection has failed (step S7), and the route collection processing is terminated.

<Processing for selecting a response terminal for a newly installed child device>
FIG. 7 is a flowchart showing response terminal selection processing of a newly installed child device, and FIG. FIG. 10 is a diagram showing a state in which the positions of surrounding terminals are grasped;

As shown in FIG. 7, the child device 2a, which is a newly installed child device, uses the positional difference information between the response terminal and the own device calculated in steps S4 and S5 in FIG. The distance to the machine and the response terminal and the direction of the base machine and the response terminal with respect to the own machine are obtained (step S11).

That is, as shown in FIG. 8, for example, using the position information of the slave device 2a as a reference (latitude 0, longitude 0), from the position difference information of the master device 1 and the slave devices 2b, 2c, and 2e which are response terminals, , the positional relationship is plotted on the coordinate axes on the RAM 23 . Arrows A1, A2, A3, and A4 in this figure represent the distances and directions of the parent device 1 and the child devices 2b, 2c, and 2e from the child device 2a.

Next, slave device 2a determines whether or not the distance to the response terminal is within the distance to master device 1 (step S12). When it is determined that the distance to the response terminal is within the distance to the base unit 1 (step S12: Yes), the direction of the response terminal to the base unit 1 and the other The direction of the response terminal to the base unit is compared (step S13), and it is determined whether the direction of the response terminal is closer to the direction of base unit 1 (step S14).

When it is determined that the direction of the response terminal is closer to the direction of base unit 1 (step S14: Yes), the response terminal is added to the route table with a higher priority than the other response terminals (step S15). ) to end the response terminal selection process. As a result, the response terminal closer to the base unit is written in the route table with higher priority.

On the other hand, if child device 2a determines that the distance to the response terminal is not within the distance to base device 1 (step S12: No), the direction of the other response terminal is closer to the direction of base device 1. If so (step 14: No), the response terminal is added to the position of the route table according to size (step S16), and the response terminal selection process is terminated.

When the child device 2a, the child device 2b, the child device 2c, and the child device 2e, which are the parent device 1 and the response terminals, have the positional relationship shown in FIG.

As shown in this table, the route table holds, as route information, a terminal ID, location information (latitude, longitude), and location difference information (latitude, longitude) for each terminal (parent device, child device). do. In addition, the route information is arranged in order of the best conditions (in order of proximity to the parent device within the distance to the parent device), and there is an upper limit to the number of route information that the route table can hold. If you do, the route information with bad conditions (arranged at the end) is deleted.

<Indication of the positional relationship between the master unit and the response slave unit with respect to the newly installed slave unit>
In the route collection processing (FIGS. 3 and 7) described above, the newly installed child device is treated as a response child device that is not suitable as a higher-level terminal, i.e., in the opposite direction (180° in FIG. 8) ~270°~0°) may be selected.

Therefore, by displaying the display shown in FIG. When a response slave unit is selected, the installation worker can cancel the selection and redo the route collection processing.

FIG. 9 is a diagram showing a display mode of the positional relationship of the parent device and the response child device with respect to the newly installed child device. Here, FIG. 9A shows a display state when the master and response slave are positioned in the same direction with respect to the newly installed slave, and FIG. On the other hand, this is the display state when the master and response slave are positioned in opposite directions.

As shown in the figure, the newly installed child device has LEDs 25a1 to 25a8 on its display unit 25, which indicate eight directions centered on its own position. In FIG. 9A, the LEDs 25a2 and 25a3 in the same direction with respect to the parent device and the response slave device are lit in red and green, and in FIG. is lit. Since the installation worker can confirm the environment in the direction of the parent device and the response slave device, it becomes easy to determine whether or not the route is appropriate.

Therefore, for example, when the display state is such that a response slave device that is not suitable as a host terminal is selected as shown in FIG. Enabled the operation to redo the In this redoing route collection processing, it is preferable to exclude the canceled response child device from the response terminal selection processing so that it will not be selected again.

In addition, the present invention makes it possible to secure a more appropriate route by combining the level of the electric field intensity (the received electric field intensity of the route search message and the received electric field intensity of the response message). That is, for example, if the electric field strength is greater than or equal to a certain value, priority is given to the direction as in the above-described embodiment, and if the electric field strength is less than the certain value, priority is given to a response terminal having a higher electric field strength than the direction.

Reference Signs List 1 Parent device 2, 2a to 2e Child device 21 CPU 22 ROM 23 RAM 25 Display unit 26 Specified low-power radio unit 28 External I/F unit 29 Antenna .

Claims (5)

A wireless communication system comprising a parent device and multiple child devices wirelessly connected to the parent device,
Each slave unit
calling means for broadcasting a route search telegram to surrounding terminals at the time of route collection;
a response receiving means for receiving a response message including the terminal ID and location information of the terminal and the location information of the parent device, which are transmitted from the surrounding terminals that received the route search message;
a direction determination means for determining the direction of the master unit and the response terminal relative to the self based on the location information of the master unit and the response terminal included in the response message and the own location information obtained by the self;
A radio communication system comprising a response terminal selection means for selecting a response terminal closer to a base unit as a higher-order terminal with higher priority when response messages are received from a plurality of surrounding terminals. In the wireless communication system according to claim 1,
Each child device has a distance determination means for determining the distance from itself to the parent device and the response terminal based on the location information of the response terminal and the parent device included in the response message and the own location information acquired by itself. have
The radio communication system in which the direction determination means determines the direction of the slave unit determined by the distance determination means to be within the distance to the master unit. In the radio communication system according to claim 1 or 2,
A radio communication system in which each slave unit has display means for displaying the base unit and the response terminal selected by the response terminal selection means centering on itself. In the wireless communication system according to claim 3,
Each slave unit has a canceling means for canceling the selection of the response terminal displayed on the display means by the response terminal selection means. In the wireless communication system according to claim 4,
The radio communication system in which the response terminal selection means does not select the response terminal canceled by the cancellation means as a higher-level terminal.

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